/*
 * Copyright 2012-2015 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package lodsve.core.condition;

import org.springframework.util.ObjectUtils;

/**
 * Outcome for a condition match, including log message.
 *
 * @author Phillip Webb
 */
public class ConditionOutcome {

    private final boolean match;

    private final String message;

    public ConditionOutcome(boolean match, String message) {
        this.match = match;
        this.message = message;
    }

    /**
     * Create a new {@link ConditionOutcome} instance for a 'match'.
     *
     * @return the {@link ConditionOutcome}
     */
    public static ConditionOutcome match() {
        return match(null);
    }

    /**
     * Create a new {@link ConditionOutcome} instance for 'match'.
     *
     * @param message the message
     * @return the {@link ConditionOutcome}
     */
    public static ConditionOutcome match(String message) {
        return new ConditionOutcome(true, message);
    }

    /**
     * Create a new {@link ConditionOutcome} instance for 'no match'.
     *
     * @param message the message
     * @return the {@link ConditionOutcome}
     */
    public static ConditionOutcome noMatch(String message) {
        return new ConditionOutcome(false, message);
    }

    /**
     * Return {@code true} if the outcome was a match.
     *
     * @return {@code true} if the outcome matches
     */
    public boolean isMatch() {
        return this.match;
    }

    /**
     * Return an outcome message or {@code null}.
     *
     * @return the message or {@code null}
     */
    public String getMessage() {
        return this.message;
    }

    @Override
    public int hashCode() {
        return ObjectUtils.hashCode(this.match) * 31
                + ObjectUtils.nullSafeHashCode(this.message);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() == obj.getClass()) {
            ConditionOutcome other = (ConditionOutcome) obj;
            return (this.match == other.match
                    && ObjectUtils.nullSafeEquals(this.message, other.message));
        }
        return super.equals(obj);
    }

    @Override
    public String toString() {
        return (this.message == null ? "" : this.message);
    }

    /**
     * Return the inverse of the specified condition outcome.
     *
     * @param outcome the outcome to inverse
     * @return the inverse of the condition outcome
     * @since 1.3.0
     */
    public static ConditionOutcome inverse(ConditionOutcome outcome) {
        return new ConditionOutcome(!outcome.isMatch(), outcome.getMessage());
    }

}
